Electric Bikes - How strong is the area where the basket support sits?

There is a bracket on the front tube of my bike above the frame that supports a basket I use. I am looking at the fork now for a way to stabilize a motor and chain drive that I want to attach to the front. If I remove the basket and standard bracket install a strong steel bracket in its place would that be strong enough to attach a motor mount to? I have tried to use paint to explain this - hope it helps.

The part you're referring to is the head tube. Its a very strong section of your bike, but one big concern is that a break there would cause you an extremely serious crash.

I don't mean to shoot down the theory of the chain front drive, its just that I don't see it being at all practical. From my perspective, I think you only have 1 option for making it work at all:

If you mount your motor onto the frame of the bike, you'd then be looking at how to deliver the power from the frame motor onto a wheel which is constantly changing orientation as you move. The only option I can think of would be belt drive, and an exposed + high speed belt in front of your face would be a really bad thing. Any sudden steering and your belt might fly off too.

The motor would have to be on the fork itself. That would let the motor move with your wheel, which would allow you to avoid worrying about how to transfer that power. Looking at this option means you'd likely need a custom made fork designed to mount the motor straight on.

In my opinion, you should probably research alternatives. I know you were looking for a high torque system, at least last time I can remember. What are your design hopes?

Don't really know what a basket support is, a front rack?

You could save weight by setting it up more like this, chain is heavy:

http://i181.photobucket.com/albums/x25/coutujean/336f8cb9.jpg

Yes! Yes! Yes! That is exactly what I am looking for :) Sorry for my obtuse posting but I started as a cycling ignoramus and am gradually progressing to the stage of cycling idiot :)

I do not really want a high torque motor but was concerned that the motor would be powerful enough to make the bike move. Then I read that powerful motors on the fork were a bit dangerous. The reason why I want to put the motor on the front end is that I want to simplify the hardware needed to make the bike go. I want what I call a hybrid bike, meaning that I can pedal with all the gears I want and still have the electric capabilities. All the rear wheel hybrids I have seen require extra freewheels and chains and who knows what all - lots more things to maintain. The Currie looks like it would fit the bill, and even mount on the rear without needing extra steel...although it would make the rear end of the bike a bit too heavy - the second reason for wanting to split it up and put it on the front end.

but....at 325 sterling - $700 - it is a bit steep! Is there any other alternative? Any way to home make one of these? The frame mount and gearing would be a little tricky....as well as finding that size motor.

but....at 325 sterling - $700 - it is a bit steep! Is there any other alternative? Any way to home make one of these? The frame mount and gearing would be a little tricky....as well as finding that size motor.

LOL... Gotta pay to play! Motor, controller and bike frame are just the tip of the Iceberg! Modern BATTERIES are the real COST to play this game.

Pengyou, the notion that front forks can only take so much is very accurate. If you're abusing your setup or running suspension, you can break a front fork with a direct drive motor, let alone something like a geared frame motor or internally geared hub motor. I have some input for you:

If you're worried about keeping the bike moving, i'm afraid the front end isn't going to offer what the rear will. Due to the decreased weight load up front, front mount e-bikes don't climb soft terrain very well. Thats not much of a concern if you're mostly on pavement, but keep it in mind if you have earthy shortcuts you take. If fork safety is a concern for you, I can speak nothing but praise for the Surly 1x1 fork: that one takes abuse like no tomorrow.

If you're worried about weight distribution with the rear wheel, one of the best fixes is to frame mount your batteries. SLA can usually be split between the middle and rear, NiMH will often fit inside a frame bag, and Lithium packs should fit inside your average triangle bag easily and conveniently. Many people also mount things on bags on top of their rear rack, but if you put your batteries into a pannier and sling them lower, you'll find the handling becomes *much* better as a result.

I'm afraid thats the only front mount frame motor i've ever seen, so unless you make your own mounts, then a hub motor is the next option, I don't think you'll be able to make one of your own for less than $700 worth of your time. At a lower budget, the best front drive option I can think of would be a Crystalyte 408, which is virtually no maintenance, good climber, but a bit lower speed at around 32/40kph depending on the voltage you put on it.

If you know someone who is good at fabrication, then maybe you could get a plate like that one made to work with a standard Cyclone/Currie, but I wouldn't try making one myself without some expertise.

Actually that currie is intended for a rear wheel, you can see the spoke proctor near the gear cluster on the other side of the wheel.

But they've also made them available for front mounting, namely on trikes. It's just that I wasn't able to find a pic of one, but they're around, I've seen such a trike on a MUP this summer.

Still, there's nothing preventing you from fabricating a metal plate to mount something like a MY1018 on a front fork, and possibly fit a wheel mounted to a 3 speed hub in there... Imagination is the only limitation really.

Actually that currie is intended for a rear wheel, you can see the spoke proctor near the gear cluster on the other side of the wheel.

But they've also made them available for front mounting, namely on trikes. It's just that I wasn't able to find a pic of one, but they're around, I've seen such a trike on a MUP this summer.

Still, there's nothing preventing you from fabricating a metal plate to mount something like a MY1018 on a front fork, and possibly fit a wheel mounted to a 3 speed hub in there... Imagination is the only limitation really.

Hm, you're right. I'd just skimmed over the image and saw what I thought was a front wheel because of the tab for a cyclometer on the spokes, something people usually front mount. Thats a rear wheel though.

I'm actually wondering if you could find a good steel fork that'll take both disks and cantilevers, run your primary anchor point as an axle mount, then use the disk tabs to hold it in place? Well, I don't know how much force would end up on the disk tabs, or whether they'd take it or not, but its a thought. Could be a way to use a normal fork and just worry about building a plate to work with it. You could use a torque arm on top of that for safety.

http://www.habcycles.com/mf63.jpg

Thanks for your insight. I think the easiest first step into the diy ebike world is going to be to mount a hub motor in the front fork. (I am also going to buy a "junker" 12 speed and start taking it apart to become more familiar with the doo-dads and doo-hickeys so I can express myself more eloquently here). It is also the least expensive - I can pick up an average quality hub motor locally for about US $50. Motor, electronics and new front wheel should set me back about $100. I am going to install a 5 speed hub gear in the rear to give me more exercise and take the pressure off my knees when I want the exercise. As someone mentioned before the killer is going to be batterie$$$. I want to replace the fork, however, and that will be tricky. I wish there was some kind of litmus test to use to determine the kind of steel something is made of. It is difficult to know if merchants here are telling the truth or not. I know steel will be magnetic. Is hard steel, i.e. 4130, "more" magnetic? Maybe a better test is the weight? How much would the fork shown in the post above (I am assuming that is chromoly) weigh? How much would a common steel fork weigh? Then to add torque arms, as was mentioned. I wish they sold this kind of bike in China but all the ebike here are really variations of scooters, with pedals added on so that you can pedal just enough to get the thing started (with the pedal first controller).

Well, I don't know of any way to find for certain that a fork is made with any particular grade of steel. You don't necessarily need a high performance fork like the 1x1, any decent steel fork should do it.

As for the hub motors, be aware that many models can look the same, but come with different variations in the copper wiring which will affect the speed/torque output. Taken straight from the ebikes.ca website:

On the Crystalyte website, you'll see a large number of motors listed and characterized like 406, 408, 409, 4011. The last digits refer to the number of turns of copper around each stator pole. So for instance, a 406 has 6 turns, the 4011 has 11 turns. This is illustrated in the diagram below
insert picture of 406 pole and 409 pole The torque that is produced by one of these motors varies in direct proportion to the total current flowing around each pole. So in the above case, a 406 motor with 15 amps flowing through the winding has a total of 90 amps around the pole. The 409 motor would need just 10 amps to have 90 amps around the pole and hence the same torque output.
One false and oft-repeated conclusion is that therefor the 409 is a higher torque motor than the 406 because it can produce the same torque with fewer amps, or likewise more torque with the same amps. This is not the case. All 400 series motors can deliver exactly the same torque at exactly the same efficiency. The lower winding count motors just need more current to do this, but because they have fewer turns of a shorter length of heavier gauge wire, they can handle high currents with minimal loss. To use a concrete example, lets compare a 406 with a 412. The 412 has twice the number of turns than the 406, so the copper wire in the windings has 1/2 the cross sectional area and twice the length, for a total of 4 times the winding resistance of the 406. For a given torque output, the 412 needs only 1/2 the amps, but because it has 4 times the resistance the net electrical loss (I2R) is exactly the same.

This relates to any direct drive hub motor, regardless of brand.

Sorry, after I read that it might be a little bit vague:
simply put, although electrical loss and efficiency from two comparative systems might be the same, picking one with more winds of copper/pole will provide more torque and less speed at a comparative current. So, if you have a chance to choose how many turns of copper you can get in your motor, pick based on your needs.

pengyou - I think you're onto a good plan. Start simple and let the process evolve so that you'll know what's what and how it can be tailored to best suit your needs. I wouldn't be too worried about steel - as long as it's steel and you don't use a monster motor, you should be fine with practically any steel. 5spd will be plenty unless you gotta lot of big hills to climb.

Batteries - don't get discouraged here. Just start with minimum AH SLA, hang 'em over the rear and work out the rest of the bike until you find yourself wishing for more range and lighter battery packs. Then you'll feel confident laying out large amounts of cash for something leading edge in that department. At this time, new and better stuff is coming along everyday so the longer you wait, the further your money will go. In the meantime, SLA will get you in the wind and give you an idea how your bike works.

best...